/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.rockcent.kcupon.zxing.view;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.view.View;

import com.google.zxing.ResultPoint;
import com.rockcent.kcupon.zxing.R;
import com.rockcent.kcupon.zxing.camera.CameraManager;

import java.util.Collection;
import java.util.HashSet;

/**
 * This view is overlaid on top of the camera preview. It adds the viewfinder rectangle and partial
 * transparency outside it, as well as the laser scanner animation and result points.
 */
public final class ViewfinderView extends View {

//    private static final int[] SCANNER_ALPHA = {0, 64, 128, 192, 255, 192, 128, 64};
    private static final long ANIMATION_DELAY = 30L;
    private static final int OPAQUE = 0xFF;
    
    private static final int CORNER_BORDER_WIDTH = 4;
    private static final int CORNER_BORDER_HALF_WIDTH = 2;
    private static final int LASER_HEIGHT = 18;
    private static final int LASER_SPEED_DISTANCE = 7;

    private final Paint mPaint;
    private Bitmap resultBitmap;
    private final int maskColor;
    private final int resultColor;
    private final int frameColor;
//    private final int laserColor;
    private final int resultPointColor;
    private Rect mLaserRect;
//    private int scannerAlpha;
    private Bitmap mLaserBitmap;
    private int mLaserPositionY = -1;
    /**
     * Laser 是否反向移动
     */
    private boolean mIsBackward = false;

    private Collection<ResultPoint> possibleResultPoints;
    private Collection<ResultPoint> lastPossibleResultPoints;

    public ViewfinderView(Context context, AttributeSet attrs) {
        super(context, attrs);

        mPaint = new Paint();
        Resources resources = getResources();
        maskColor = resources.getColor(R.color.viewfinder_mask);
        resultColor = resources.getColor(R.color.result_view);
        frameColor = resources.getColor(R.color.viewfinder_frame);
//        laserColor = resources.getColor(R.color.viewfinder_laser);
        resultPointColor = resources.getColor(R.color.possible_result_points);
//        scannerAlpha = 0;
        mLaserRect = new Rect();
        mLaserBitmap = ((BitmapDrawable) (getResources().getDrawable(R.drawable.qrcode_scan_line)))
                .getBitmap();
        possibleResultPoints = new HashSet<ResultPoint>(5);
    }

    @Override
    public void onDraw(Canvas canvas) {
        //中间的扫描框，你要修改扫描框的大小，去CameraManager里面修改
        Rect frame = CameraManager.get().getFramingRect();
        if (frame == null) {
            return;
        }

        int width = canvas.getWidth();
        int height = canvas.getHeight();

        // Draw the exterior (i.e. outside the framing rect) darkened
        mPaint.setColor(resultBitmap != null ? resultColor : maskColor);
        canvas.drawRect(0, 0, width, frame.top, mPaint);
        canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, mPaint);
        canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, mPaint);
        canvas.drawRect(0, frame.bottom + 1, width, height, mPaint);

        if (resultBitmap != null) {
            // Draw the opaque result bitmap over the scanning rectangle
            mPaint.setAlpha(OPAQUE);
            canvas.drawBitmap(resultBitmap, frame.left, frame.top, mPaint);
        } else {
            drawCorner(canvas, frame);
            drawLaserLine(canvas, frame);

            // Draw a two pixel solid black border inside the framing rect
            // mPaint.setColor(frameColor);
            // canvas.drawRect(frame.left, frame.top, frame.right + 1, frame.top + 2, mPaint);
            // canvas.drawRect(frame.left, frame.top + 2, frame.left + 2, frame.bottom - 1, mPaint);
            // canvas.drawRect(frame.right - 1, frame.top, frame.right + 1, frame.bottom - 1, mPaint);
            // canvas.drawRect(frame.left, frame.bottom - 1, frame.right + 1, frame.bottom + 1, mPaint);

            // Draw a red "laser scanner" line through the middle to show decoding is active
            // mPaint.setColor(laserColor);
            // mPaint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
            // scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
            // int middle = frame.height() / 2 + frame.top;
            // canvas.drawRect(frame.left + 2, middle - 1, frame.right - 1, middle + 2, mPaint);

            Collection<ResultPoint> currentPossible = possibleResultPoints;
            Collection<ResultPoint> currentLast = lastPossibleResultPoints;
            if (currentPossible.isEmpty()) {
                lastPossibleResultPoints = null;
            } else {
                possibleResultPoints = new HashSet<ResultPoint>(5);
                lastPossibleResultPoints = currentPossible;
                mPaint.setAlpha(OPAQUE);
                mPaint.setColor(resultPointColor);
                for (ResultPoint point : currentPossible) {
                    canvas.drawCircle(
                            frame.left + point.getX(), frame.top + point.getY(), 6.0f, mPaint);
                }
            }
            if (currentLast != null) {
                mPaint.setAlpha(OPAQUE / 2);
                mPaint.setColor(resultPointColor);
                for (ResultPoint point : currentLast) {
                    canvas.drawCircle(
                            frame.left + point.getX(), frame.top + point.getY(), 3.0f, mPaint);
                }
            }

            // Request another update at the animation interval, but only repaint the laser line,
            // not the entire viewfinder mask.
            postInvalidateDelayed(
                    ANIMATION_DELAY, frame.left, frame.top, frame.right, frame.bottom);
        }
    }

    private void drawCorner(Canvas canvas, Rect frame) {
        int borderOffset = (frame.right - frame.left) / 5;
        mPaint.setColor(frameColor);
        canvas.drawRect(
                frame.left - CORNER_BORDER_WIDTH,
                frame.top - CORNER_BORDER_WIDTH,
                frame.left + borderOffset,
                frame.top + CORNER_BORDER_HALF_WIDTH, mPaint);
        canvas.drawRect(
                frame.right - borderOffset,
                frame.top - CORNER_BORDER_WIDTH,
                frame.right + CORNER_BORDER_WIDTH,
                frame.top + CORNER_BORDER_HALF_WIDTH,
                mPaint);
        canvas.drawRect(
                frame.left - CORNER_BORDER_WIDTH,
                frame.top + CORNER_BORDER_HALF_WIDTH,
                frame.left + CORNER_BORDER_HALF_WIDTH,
                frame.top + borderOffset - CORNER_BORDER_HALF_WIDTH,
                mPaint);
        canvas.drawRect(
                frame.right - CORNER_BORDER_HALF_WIDTH,
                frame.top + CORNER_BORDER_HALF_WIDTH,
                frame.right + CORNER_BORDER_WIDTH,
                frame.top + borderOffset - CORNER_BORDER_HALF_WIDTH,
                mPaint);
        canvas.drawRect(
                frame.left - CORNER_BORDER_WIDTH,
                frame.bottom - borderOffset,
                frame.left + CORNER_BORDER_HALF_WIDTH,
                frame.bottom - CORNER_BORDER_HALF_WIDTH,
                mPaint);
        canvas.drawRect(
                frame.right - CORNER_BORDER_HALF_WIDTH,
                frame.bottom - borderOffset,
                frame.right + CORNER_BORDER_WIDTH,
                frame.bottom - CORNER_BORDER_HALF_WIDTH,
                mPaint);
        canvas.drawRect(
                frame.left - CORNER_BORDER_WIDTH,
                frame.bottom - CORNER_BORDER_HALF_WIDTH,
                frame.left + borderOffset,
                frame.bottom + CORNER_BORDER_WIDTH,
                mPaint);
        canvas.drawRect(
                frame.right - borderOffset,
                frame.bottom - CORNER_BORDER_HALF_WIDTH,
                frame.right + CORNER_BORDER_WIDTH,
                frame.bottom + CORNER_BORDER_WIDTH,
                mPaint);
    }

    private void drawLaserLine(Canvas canvas, Rect frame) {
        initialLaserPositionY(frame);
        mLaserRect.left = frame.left;
        mLaserRect.right = frame.right;
        mLaserRect.top = mLaserPositionY;
        mLaserRect.bottom = mLaserPositionY + LASER_HEIGHT;
        canvas.drawBitmap(mLaserBitmap, null, mLaserRect, mPaint);
    }

    private void initialLaserPositionY(Rect frame) {
        final int laserTop = frame.top;
        final int laserBottom = frame.bottom;
        if (mLaserPositionY < 0) {
            mLaserPositionY = laserTop;
        }

        if (!mIsBackward) {
            mLaserPositionY += LASER_SPEED_DISTANCE;
        } else {
            mLaserPositionY -= LASER_SPEED_DISTANCE;
        }

        if (mLaserPositionY >= laserBottom - LASER_HEIGHT) { // Cause positionY is based on top
            mIsBackward = true;
        }
        if (mLaserPositionY <= laserTop) {
            mIsBackward = false;
        }
    }

    public void drawViewfinder() {
        resultBitmap = null;
        invalidate();
    }

//    /**
//     * Draw a bitmap with the result points highlighted instead of the live scanning display.
//     *
//     * @param barcode An image of the decoded barcode.
//     */
//    public void drawResultBitmap(Bitmap barcode) {
//        resultBitmap = barcode;
//        invalidate();
//    }

    public void addPossibleResultPoint(ResultPoint point) {
        possibleResultPoints.add(point);
    }

}
